Credit cards have been used for the purpose of identification, payment, credit inquiry, and the like. Recently, in addition to a service, a discount rate, and a mileage point of a credit car, a pattern and design of the credit card have become important factors of selecting the credit card. Therefore, card manufacturers have tried to satisfy various clients' requests by contriving cards having much difference in functions as well as in pattern and design of the credit cards.
As an example of the approaches, Korean Patent Application No. 10-2007-0121197 is disclosed. The patent document discloses a card including a metal sheet for a metal card and a fixing piece coupled with the metal sheet, so that improved nobleness can be provided to the card due to its gloss unique to a metal.
However, although the gloss unique to a metal can be provided to the above-described metal card, since the surface of the credit card is simple in pattern and design, there is a limitation in satisfying various clients' requests.
In addition, since the above-described metal card cannot secure insulation, there is a problem in that it is impossible to employ a contact IC chip. Recently, in order to prevent illegal reproduction of credit cards using magnetic stripes, the contact IC chips need to be configured. The securing the insulation of the metal card has been actively researched.
In addition, although the above-described metal card has high strength, there is a problem in that it is difficult to stably attach a back-surface attachment member such as a magnetic film and a signature plate on a surface of the metal card. This is because an adhesive force of an adhesive with respect to the metal card is weaker than the adhesive having a strong adhesive force with respect to a plastic card.